Our wheel bearing greasing tool is designed to grease your wheel bearings. Please be sure to carefully check our pictures and descriptions of the PRODUCT SIZE. The Grease Tools are constructed from high-quality material 6063 Aluminum Alloy construction, Knurl surfaces provide a non-slip grip, attached with 1 stainless steel cotter pin, quite durable, upgrading your wheel bearing and making it work better. Double O-Ring seals keep the grease inside of the bearings, which also spread the inner bearing races apart to allow a gap for the grease to easily flow inside. Easy job, Simply inserts the tool into your bearing and pump grease through Zerk fitting with your grease gun.